Cranioplasty cancelled

Oops my message didn't go along with my title! My 22 yr old son was scheduled for his cranioplasty yesterday. He had a bleed Oct 8th, and a craniectomy. He got to the hospital and was admitted and sedated. About 20 minutes later the surgeon comes out and say that he decided that he isn't ready for the surgery-- still too much swelling and fluid. My son was very disappointed when he woke up. What is the average wait for a cranioplasty? Are there things you can do to help make the swelling (fluid) go down? Glad he waited if there could be complications, but very frustrating they couldn't figure it out before he was prepped for surgery! He is waiting to have gamma knife surgery for his AVM, and the crainioplasty has to come first.